Diamond cutting solid link chain is a well-known art, and is usually accomplished by shearing off a section of the exterior surface of the exposed chain links to form a facet thereon. Faceting with flattened surfaces is also a well known method of enhancing the aesthetic appeal of a jewelry chain, and several different methods have developed in the art to carry out the faceting thereof.
Faceting of hollow link jewelry chain, on the other hand, requires more specialized attention. For example, if a portion of the exterior surface of a hollow link chain was sheared off, as is normally done with solid link chain, the likely result will be a hole therethrough and not a smooth, flattened surface thereon. Jewelry chains formed by intertwining hollow chain links are particularly problematic, because the material used to form the links is usually very thin, and thus very susceptible to perforation. However, in U.S. Pat. No. 5,966,922 to Cossio, the material limitations that caused perforations in the prior art are overcome by tempering and precisely positioning the chain prior to diamond cutting.
One solution for faceting hollow link jewelry chain is disclosed in U.S. Pat. Nos. 5,129,220 and 5,353,584, both to Strobel. Strobel provided for a flattening of the links, i.e., without the removal of any surface material. He used the ice lathe method where the links were frozen, and then he applied a blunt instrument to pound the links incrementally, thereby flattening them. Once the links were flattened, it was possible to diamond cut or polish them as desired. Strobel's method only covers the incrementally pounding of links, which has been determined to not be a very commercially efficient method. Other methods that do not rely on the use of an ice lathe are also known in the art, including a method of faceting hollow link jewelry chain wherein a chain is moved continuously over pulley guides whereon the exposed chain surface is deformed without removal of chain material as taught in U.S. Pat. No. 5,535,583 to Holzer et al.
An improvement in the art of faceting hollow link jewelry chain was revealed in U.S. Pat. No. 5,605,038 to Rosenwasser, wherein it was disclosed to use a pressure roller that freely rotates to flatten links. However, the '038 patent is limited to a Garibaldi type chain. In Rosenwasser's CIP, which issued as U.S. Pat. No. 5,737,910, he broadens the initial concept by applying a pressure roller to any link, presumably including rope chain links. Additionally, throughout both the '038 and '910 patents, Rosenwasser indicates that in using the pressure roller, only the lower portion of the links should be frozen using the ice lathe method, while the upper portions to be rolled with a pressure roller should be free of ice. Rosenwasser teaches that "In the case of hollow rope chains, only the lower half of the chain is embedded in ice near the drum surface, since if one were to cover the entire chain with ice it would be difficult to form a flat indentation in the annular link, because solid ice formed inside the hollow link would resist the deformation of the link wall." (see Col. 2, lines 14-20 of the '038 patent).
Rosenwasser's method requiring that a portion of the chain be defrosted prior to flattening is currently the state of the art. Unfortunately, great care must be taken to ensure that a portion of the chain remains ice-free during the flattening or faceting process. This usually involves the controlled freezing of the chain, followed by a controlled heating, usually by a heating mantle, where the upper layer of ice surrounding the outermost portions of the chain is slowly and controllably melted away. The controlled freezing and heating of hollow link jewelry chain for purposes of flattening and/or faceting is an unwelcome manufacturing hassle, because it increases the time of manufacture and cost of production, which results in an increased cost borne by the consumer.
In an effort to reduce costs and simplify the manufacturing process, the present inventor has devised a method of continuous flattening of a hollow link jewelry chain without requiring that a portion of the chain remain ice-free. According to the method of the present invention, a hollow link chain is completely frozen on a supporting drum of an ice lathe for example. Without defrosting any portion of the chain, a blunt instrument, such as a so-called "finger of steel" is advanced across the outer surface of the chain, which simultaneously scrapes off the surface layer of ice from the chain and flattens the links that form the chain. The pressure of the instrument against the surface of the chain crushes or melts some ice formed on the inside of the hollow links, thereby overcoming the problem described by Rosenwasser above.
Once a hollow link jewelry chain is wound and frozen using the ice lathe method described above, the type of facets that can be made depend upon the ones that are desired. For example, as the drum is rotated and the blunt instrument is just moved horizontally, the result will be a flat facet along one side of the chain. The chain can then be repositioned in 90 degree increments to get four flat facets on four sides of the chain. Alternately, six sides, eight sides, etc., can be faceted. On the other hand, if the instrument is arcuate at its contact with the chain, a spiral type facet can be made as per U.S. Pat. No. 5,285,625 to Ofrat et al.